Guarantees

U.S. GAAP requires that upon issuance of a guarantee, the guarantor must recognize a liability for the fair value of the obligation it assumes under that guarantee. In addition, U.S. GAAP requires disclosures about the guarantees that an entity has issued, including a tabular reconciliation of the changes of the entity’s product warranty liabilities.

Accrual for Product Warranty Liabilities

We record a reduction to revenue for estimated product returns at the time revenue is recognized primarily based on historical return rates. Cost of revenue includes the estimated cost of product warranties. Under limited circumstances, we may offer an extended limited warranty to customers for certain products. Additionally, we accrue for known warranty and indemnification issues if a loss is probable and can be reasonably estimated.

The estimated product returns and estimated product warranty liabilities as of April 30, 2017 and January 29, 2017 were as follows:



	April 30,			January 29,
	2017			2017
	(In millions)
Balance at beginning of period	$	8		$	11
Additions	—			2
Deductions	(1		)	(5		)
Balance at end of period	$	7		$	8

In connection with certain agreements that we have entered into in the past, we have provided indemnities to cover the indemnified party for matters such as tax, product, and employee liabilities. We have included intellectual property indemnification provisions in our technology related agreements with third parties. Maximum potential future payments cannot be estimated because many of these agreements do not have a maximum stated liability. We have not recorded any liability in our Condensed Consolidated Financial Statements for such indemnifications.